JS-Kit/Echo comments for article at http://smallestminority.blogspot.com/2008/04/range-report.html (17 comments)

  Tentative mapping of comments to original article, corrections solicited.

jsid-1209250130-591421  USCitizen at Sat, 26 Apr 2008 22:48:50 +0000

Impressive groups. Glad the scope's doin' it's part.

jsid-1209257602-591423  Jim Gwyn at Sun, 27 Apr 2008 00:53:22 +0000

I concur with the Citizen. I'd be proud to have shot the groups.

As to the question, pressure, maybe.

According to the real numbers that have become more common in recent years, primer cratering may or may not be an indicator of excessive pressure. I note that the primers don't seem to be flattened to any great degree.

Are your loads showing any other symptoms such as sticky extraction, etc.?

You might want to load a few softer loads to see how the primers compare with these.

jsid-1209270920-591426  Kevin Baker at Sun, 27 Apr 2008 04:35:20 +0000

There's a little bit of primer flattening that you really can't see in this shot. I think I'm going to drop down to 42.0 grains of Varget. This guy is getting good results with that load in his 5R: Tobystatical

Then may work my way up in 1/10th grain increments to 43.0 checking accuracy at each step.

I'm really interested in how the 155 grain Scenars shoot, though.

jsid-1209421862-591445  DirtCrashr at Mon, 28 Apr 2008 22:31:02 +0000

I know with all the crap I haul around I'm about ready for one of these: http://www.kaddykarts.com/
Sweet group BTW!!

jsid-1209422390-591446  DJ at Mon, 28 Apr 2008 22:39:50 +0000

Those primers look a mite hot to me. Do you have a Wolff heavy mainspring behind the firing pin?

jsid-1209423832-591447  Kevin Baker at Mon, 28 Apr 2008 23:03:52 +0000

No, other than the Gunkote finish, that rifle is stock-out-of-the-box.

jsid-1209424397-591448  DJ at Mon, 28 Apr 2008 23:13:17 +0000

As you probably know, a weak main spring will exaggerate primer cratering. Many years ago (1977 or thereabouts), I replaced the stock spring on my Model 70 with a Wolff heavy duty spring. Signs of primer cratering disappeared. I replaced that same spring last fall. The Wolff spring I replaced was still stronger than the original, which I still have, even after 31 years of use.

It's just food for thought.

jsid-1209425574-591449  Kevin Baker at Mon, 28 Apr 2008 23:32:54 +0000

Well, the next load I'm going to try for this rifle is 42.0 grains of Varget. If I'm still seeing cratering, I might look at replacing the firing pin spring. Thanks for the suggestion.

jsid-1209446883-591455  Nate at Tue, 29 Apr 2008 05:28:03 +0000

I make target stands from 2" PVC, glued into a 2' square with 2 "T"s opposite each other. 2X2 posts trimmed down to fit into the uprights provide stapling space. They cost nothing to make, transport easy, are light enough to carry to the shooting distance you want and work remarkably well.

jsid-1209455106-591457  Mike at Tue, 29 Apr 2008 07:45:06 +0000

Hmm, I've been shooting the same 175 SMKs, but using 44.2 grains of Varget. My bone-stock Rem 700 PSS prefers that load.

jsid-1209476997-591470  Kevin Baker at Tue, 29 Apr 2008 13:49:57 +0000

Mike, every gun is different. What works perfectly in yours might be unsafe in mine. I found some load data last night that suggests that 43.5 grains of Varget will produce about 59000psi, and is "near maximum". Apparently that's correct for my rifle, but not yours.

Nate, I've seen people with frames similar to what you recommend. I think that's the way I'm going to go, since I don't own a welder and I no longer work at a place with a fab shop.

jsid-1209495859-591488  Joe Huffman at Tue, 29 Apr 2008 19:04:19 +0000

Looks like you are getting ready for Boomershoot 2009. Will I be seeing you there?

jsid-1209497697-591489  Kevin Baker at Tue, 29 Apr 2008 19:34:57 +0000

I'm not promising anything, but I'll give you a definite "maybe" right now.

jsid-1209500418-591492  Joe Huffman at Tue, 29 Apr 2008 20:20:18 +0000

I'll send you an email when registration opens up (probably within a month). Sign up then you can cancel with a full refund later on if things don't work out.

jsid-1209525144-591506  Firehand at Wed, 30 Apr 2008 03:12:24 +0000

Few years back took the son to the range and found it was just us and some guy sighting in for deer season. VERY loud rifle, and during a break I asked what he was shooting. "7mm Magnum. They're a little hot, but they don't flatten the primers TOO much, so I'll use them." At which I thought seriously about moving as far away from his bench as we could get.

What made that even more damn silly was where he was planning to hunt: southern OK, where a LOOONG shot is 200 yards.

jsid-1209526325-591509  Kevin Baker at Wed, 30 Apr 2008 03:32:05 +0000

Realistically, Firehand, "slightly flattened" primers aren't necessarily indicators of dangerous pressures. They can even be a sign of low pressure (though I doubt it was the case in your example.)

Of course, when I see slightly flattened primers, I BACK THE LOAD OFF.

I like long case life, and I don't like beating my rifles up.

Cratering, on the other hand, is a new one on me - at least as much cratering as I saw here.

jsid-1209578015-591524  DJ at Wed, 30 Apr 2008 17:53:35 +0000

There's another trick to pressure management that I've found useful. I police the brass at the range to find spent factory loads in the cartridges that I shoot. The pressure signs of my handloads don't look any hotter than they do, so if they are hotter, it ain't by much.

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